Telephone-meter unit



Patented Nov. 6, 1928.

, UNITED STATES PATENT OFFICE.

GEORG TAUCHMANN, OF BERLIN-SCHONEBERG, GERMANY, ASSIGNOR TO SIEMENS &

HALSKE AKTIENGESEILSCHAFT, WERNERWERK, OF SIEMENSSTADT, NEAR BER- LIN, GERMANY.

TELEPHONE-METER UNIT.

Application filed April 3, 1926, Serial No. 99,444, and in Germany June 4, 1925.

This invention relates in general to telephone systems, more especially to measured service systems in which charges are levied against a line in accordance with the length of the conversation.

Specifically the invention relates to an improved elapsed time meter unit, which is so constructed as to fit into the space occupied by the trunk keys of a manual switchboard.

In modern telephone systems there are many classes of calls in which the charge is based upon the length of the conversation, and for this purpose various elapsed time metering systems have been devised. Some of these call classes, for example, person to person toll calls, warrant the use of an elapsed time meter which prints upon a ticket the starting and finished time of the conversation. The equipment for this purpose is expensive and its use is warranted only when the charge for service is relatively heavy, as it would be in the case of a person to person toll-connection.

Other classes of measured service, for example, station to station calls between adjacent exchange areas, are assessed at a substantially lower rate, a rate which is so low as to render the use of this'expensive time recording equipment impractical. In the past calls of such class have been metered by means of a message register which is periodically operated to indicate a measure of the elapsed time, the operator noting this reading, records the time on a ticket manually.

Elapsed time meters of different kinds that have been used heretofore in telephone exchanges have required special mountings and locations because the design of such meters has not permitted their location either on the key shelf or jack panel of the switchboard. This wide separation of the meter from the trunk circuit it serves imposes an additional duty on the operator and takes her attention from her main duties at the switchboard. The principal object of this invention is, therefore, the design of a meter unit comprising the necessary meter and supervisory equipment so designed and arranged as to permit its mounting on the key shelf or jack panel of the switchboard in close association with the trunk circuit that it serves.

The drawings comprising Figs. 1 to 4, inelusive, show one embodiment of my invention.

Figure 1 shows a section of the key shelf of an ordinary manual switchboard, showing the plugs FS and FS the supervisory lamp FSL and FSL and the key escutcheon containing keys FTU, FBU, an d FAU, shown irr the manner in which they are ordinarily associated with each other. To the right of the key cscutcheon I have shown a metering escutcheon ZE- containing the meter units built in accordance with the objects of this invention.

Figure 2 shows a plan view of the metering unit, which comprises the escutcheon 6 through which the operating key 9, restoring key S. and the lamp signal 7 protrude. The register comprising the minutes wheel 11 and the seconds wheel 12 are visible through the opening 10 in the escutcheon.

Figure 3, which is an elevation View of the metering unit shows a detailed arrangement of the equipment.

Figure 4 is an end view of Fig. 3 taken through the line 4-4.

Referring now particularly to Fig. 3, the metering unit is assembled upon the main mounting plate 1, which is approximately the same size as the key escutcheon of an ordinary manual switchboard. Attached to this mounting base is the supervisory lamp jack 4, which holds the supervisory lamp visible through the lamp cap 7. This jack may be of any well known type and does not form an essential part of the invention. The operating key comprising handle 9 and its associated equipment is mounted upon the usual key mounting frame 2, this key structure being familiar to those skilled in the art and not an essential part of this invention. The metering unit proper which forms the principal part of this invention, is mounted upon the frame work 18, and consists of the register wheels 11 and 12, together with the ratchet wheel 19 and the rcsetting cam 20 for controlling them. The magnet 17 upon being energized attracts the armature 16, moving the projection carrying pawl 18 to the left, causing the pawl to advance the register wheel 12 one step. The register wheel 12 is held in its set position by means of the retaining spring 21, which bears against the teeth of the ratchet wheel 19, thereby preventing its backward movement. When the magnet is deenergi'zed the spring 33 returns the armature and pawl back against the backstop, which is mounted on the armature screw 32. As shown, the register wheel 12 is calibrated in 5 second intervals and is coupled to the register wheel 11 by suitable mechanism sot-hat the latter takes one step for each revolution of the former. By this arrangement if the magnet 17 is energized every five seconds the indicat-ion on the register wheels 11 and 12 will be minutes and seconds, respectively. Attached to the register 12is a button 28, which is arranged to engage the springs 29 at one interval during the rotation of the register. By this arrangement a circuit can be closed to the supervisory lamp visible through the cap 7 atv some definite interval during the conversation. v If, for example, the unit conversational period is three minutes, this circuit could be arranged to be closed shortly before the end of that interval, so that the operator can connect her telephone to the cord circuit and inform the parties that their initial conversation period has about elapsed and that-they will be charged additional in a short time. This is in accordance with the well known practice of operating companies.

When the conversation is completed and the operator has noted the elapsed time thereof and made out the required tickets, she restores the meter mechanism to normal by opperating the push button 8, which presses down upon the cam lever 23, causing it to turn about the pivot pin 24. The right-hand of the lever 23 contains a pin 23', which bears against a cam shaped section of the pawl 18, causing the latter to rotate about its axis and withdraw the pawl from the teeth of the ratchet wheel 19. The left-hand end 25 of the restoring lever contains a pin 26 which in traveling upward responsive to the operation of thepush-button 8 bears against the cam-like section of'qthe retaining spring 21 moving it to the left out of engagement with the teeth of the. ratchet wheel 19. As the lever .25., is rotated further the cam portion 27 connas intojcontact with the surface of the heart cam 20 0f the register wheel 12 returning that wheel to its normal position by the shortest path possible in the Well known manner. When the operator removes the pressure from the push button 8, spring 22 returns the lever 23 and the push button 8. to their normal position and the meter unit is in readiness for the next call.

Although the metering circuits do not form a part of this invention it will be understood that the switch key 9 is provided to close the metering circuit. In accordance with the established practice conversation period hegins when the called party answers, at which time the operator will manipulate the key 9 to connect the magnet 17 of the metering unitto the source of interrupted. battery, which is arranged to send a pulse of battery current to the magnet at stated intervals assumed to be five seconds. WVhen the supervisory lamps F SL and FSL apprise the operator of the completion of the connection, sherestores the key 9 to prevent the further assessing of charges should it be necessary for her to delay momentarily in the restoration of the metering equipment.

I Having thus described my invention what I consider new and desire to have protected by Letters Patent is pointed out in the ap pended claims.

Wha-tis claimed is: v

1. In a meter unit having an operating mechanism for the counting discs, consisting of a ratchet wheel and normally engaged operating and holding pawls, a restormg mechanism consisting of a cam and a restoring lever, said lever pivoted at a central point and having a pin on each side of the pivot point, one pin engaging the holding pawl and the other pin engaging the operating pawl when the lever is operated, to disengage both from the ratchet wheel.

2. In a meter unit having an operating mechanism consisting of a ratchet wheel and a pair'of normally engaged pawls, a centrally pivoted restoring lever having means at one end for engaging one'pawl and means at the other end to engage the other pawl, and means for operating said lever to thereby disengage both pawls-gwhen restoring the unit.

3. In a meter unit having an operating mechanism consisting of a ratchet wheel anda pair of normally engaged pawls, a central- 1y pivoted restoring lever having a pin on each side of the pivot point, one of said pins 100 engaging one pawl and the other pin engaging the other pawl, and means for moving said lever about its pivot point to thereby disenga e said pawls from the ratchet wheel.

n witness whereof, I hereunto subscribe 1 my-name this 19th 1926.

GEORG TAUCHMANN.

day of January, A. D. 

